Combination carburetor and ignition system



M. MALLORY Original Filed March 2, 1942 Oct. 26, 1943.

COMBINATION CARBURETOR AND IGNITION SYSTEM INVENTOR'. MARION MALLORY Patented Oct. 26, 1943 COMBINATION czmnomrron AND I rcNrrromsrs'rsm Marion Mallory, Detroit, Mich.

Original application March 2,

Divided and this application June 1, 1942, Serial No. 445,31!

1942, Serial No.

4 Claims. (Cl. 123117) This invention relates to a combination carburetor and ignition system.

In most present day carburetors the fuel jet is positioned between the throttl valve and atmosphere. The vaporizing of the fuel as it flows from the fuel nozzle creates refrigeration which frequently causes the throttle to freeze, and in particular where the carburetor is used in an airplane flying at high altitude.

One of the features of-this of producing a carburetor wherein the fuel nozzle is positioned between the throttle and the engine so that the atomized fuel mixtures do not freeze on the throttle or in the carburetor body because the atomization takes place in or adjacent to the hot spot located in the intak manifold on the engine side of the throttle valve.

Another feature of this invention is that condensation of the atomized fuel is prevented. Since the fuel nozzle is positioned on the outlet sid of the throttle valve 'the atomized fuel cannot strike the cold throttle valve or cold walls of the carburetor which would cause condensation of the fuel.

Another object of the invention is that of premixing or atomizing a metered amount of fuel with a metered amount of air before the atomized mixture passes out of the fuel nozzle into the venturi or mixing chamber of the carburetor where it is mixed with additional amounts of air flowing through the main passageway of the carburetor.

invention is thatof shaft 13. Thus, if unbalanced valve 2 is unrestricted, the vacuum in the manifold will open thevalve due to its unbalanced nature.

This invention also contemplates a carburetor and ignition system in which the ignition timing is controlled entirely by the charge flowing through the carburetor venturi at wide open throttle, that is, under full load conditions, and controlled principally by the vacuum existing in the manifold on the engine side of the throttle valve when the carburetor is operating under all conditions except wide open throttle or at idle position of the throttle.

The figure is a vertical cross sectional View through the carburetor and ignition system.

Referring more particularly to the drawing, the carburetor housing is designated 30 and is provided with an air inlet 3! and a fuel and air outlet 32 on the engine side of the throttle valve 2 mounted on valve shaft l3. Valve shaft is is journaled in the housing 30 in a conventional manner. Valve 2 i an unbalanced throttle valve,

that is, the area of the throttle valve 2 on one side of the'shaft l3, or to the right of shaft i3, is greater than the area of the portion of the throttle valve on the otherside, or to the left The manually controlled throttle rod I2 is pivotally connected to. throttle arm or plate 33 which is journaled on shaft l3 with a lost motion connection and exterior of the housing 30. An arm 3 is fixed on the same end of shaft 13 as plate 33, also exterior of the housing 30. Plate 33 is provided with the spaced lugs 35 and 36 which engage opposite sides of arm 34 when plate 33 is turned on shafti3. The lugs 35 and 36 are spaced so that there is a 10st motion between shaft 13 and plate 33 when the plate is rotated by rod i2. In other words, if plate 33 is held still, arm 34 is free to rotate between lugs 35 and 36. This 10st motion, as shown by way of description rather than for purposes of limitation, amounts to about 20.

A link it is pivotally connected at one end with plate 33 and at the other end with metering pin G which slides up and down in passageway 3i and controls orifice 6. Orifice 6 connects into passageway Ii. The upper end of passageway ii communicates with atmosphere through orifice id and the lower end of passageway ii communicates with the interior of the float bowl 38 of the carburetor through orifice i. Passageway 3i communicates through passageway 8 and fuel orifice 39 with the venturi 9 of the main carburetor passageway.

The'arm 3% is connected by rod to with diaphragm ll of a suction device 15 backed up by a compression spring it which tends to hold the throttle valve 2 in idle position asshown. The suction device If: communicates by means of conduit A2 with quill I t positioned in the intake passageway on the atmosphere side of the throttle valve. The left hand side of the diaphragm ll is open to atmosphere whereas the right hand side of the diaphragm ii and the interior of the right hand portionof the suction device l5 communicates with atmosphere only through conduit 52, quill id and the intake passageway of the carburetor.

The operation of the carburetor as thus far described is as follows: Assume that throttle valve 2 is practically closed, that is, just open enough to permit a sufilcient charge of air to flow by the throttle for idling of the engine, at this time the metering pin 6 is almost closed but permits enough fuel to flow through orifice 6 for the engine to idle. This fuel passes from the float I bowl into channel I, through orifice B, passageways Sl and B, and through nozzle 39 into the venturi 9. Simultaneously with the flow of fuel through orifice 6, air passes through orifice l9 into passageway II and into orifice 6 where it intermixes with the fuel and flows with the fuel through passageways 31 and 8 and orifice 39 into venturi 9, where this rich mixture of fuel and air is further intermixed with the main air charge flowing through the main passageway of the carburetor and venturi 9. As the throttle 2 is moved towards open position from idle more air and more fuel are admitted through orifice 6 because the metering pin with its tapered face 43 is raised. Thus, the air and fuel passing through orifice 6 are metered simultaneously and through the same orifice.

If the throttle rod I2 is pulled toward the left in Fig. 1 to open the throttle 2, the rod 2 and arm 33, due to the lost motion connection with arm 34, will move a considerable distance before the manifold suction begins to open the throttle valve and as the throttle rod-is pulled or moved outwardly or to the left, the metering pin 4 will move a considerable distance upwardly before the throttle valve starts to open. This makes the fuel mixture a little richer for sudden acceleration. As the engine speeds up following the partial opening of the unbalanced throttle valve 2 by the suction, the air velocity past quill |4 causes the diaphragm in suction device l5 t open valve '2 against the force of compression spring |6 within the limits permitted by stop lugs 35 and 36 on arm 33. Of course, if the throttle rod 2 is pulled wide open or to the left, then clockwise rotation of arm 33 causes lug 36 to engage the left hand edge of arm 34 to rotate the same clockwise and open the throttle valve wide in spite of spring |6 which is compressed by this manual opening of the throttle valve 2.

The timing mechanism is conventional and as shown consists of the usual rotatable cam 46 which operates the electrical circuit breaker 41. The circuit breaker 47 is mounted on the plate 48 which can be rotated clockwise to advance the spark and counterclockwise to retard the spark. A suction device 20 is used for advancing and retarding the spark. This suction device comprises a flexible diaphragm 49 backed up by a compression coil spring 59. The diaphragm 49 is mounted in the housing 5| which is connected to the carburetor by conduit 52. The diaphragm is connected to plate 48 by connecting rod 53, one end of which is pivotally connected to the plate 48 and the other end of which is fixed to the diaphragm. The left hand wall of the housing 5| is perforated so that the diaphragm is subjected on the outside, or left hand side as viewed in the rawing, to atmospheric pressure whereas the inside of the housing 5|, that is, the right hand side of the diaphragm 49, is subjected through conduit 52, orifice 9 and passageway H and orifice 23 to the vacuum created by the flow or velocity of the air through venturi 9 and by orifice 23. Communication between orifice |9 and passageway I1 is controlled by valve I8 and compression spring 2| which normally tends to elevate valve l8 thereby permitting communication between orifice l9 and passageway Passageway 55 communicates at one end with orifice 22 positioned in the intake passageway on the atmosphere side of throttle valve 2 and the other end of passageway 55 continuously,communicates with conduit 52.

The ignition timing operates as follows: The vacuum on the engine side of valve 2 is always highest when the valve is closed for idling and the engine is idling. At this time the manifold suction acts through passageway I! to draw piston valve l8 downwardly against spring 2| and thereby shut off orifice |9. In other words, when valve l8 closes orifice l9, suction device is shut off from communication with the engine manifold suction. As the throttle 2 is moved towards an open position, as above described, the suction'in the manifold will decrease and spring 2| will move piston l8 upwardly to clear or open orifice |9 thereby placing the suction device in communication with the intake passageway below throttle valve 2 and thereby sub- I jecting the suction device to the intake manifold vacuum which advances the spark for light load or part throttle operation. The orifice 22 bleeds the manifold suction down under part load or part open throttle conditions, particularly at slow engine speeds, so that the spark is not advanced far enough to cause detonation or preignition. This bleeding down of the manifold vacuum permits one to use the same suction device for controlling the ignition by use of the manifold suction as well as the suction created by the velocity of air flowing through the ven- 'ful than the manifold suction at idle or turi. The venturi created suction is less powerpart throttle. By bleeding the suction down at part load or part open throttle when the manifold suction is high, one can use the same suction'device not only under part open throttle conditions but also under wide open throttle conditions when the venturi created suction is less powerful and yet obtain the required advance of the spark as the speed of the engine or velocity of air through the venturi increases. When the throttle 2 is wide open the ignition is timed by the vacuum or suction created by the flow of air by orifice 23 in venturi 9 so that as the speed of the engine increases under wide open throttle the vacuum at orifice 23, which is applied through passageways I! and 52 on diaphragm 49, advances the spark correspondingly.

The outlet end 32 of the carburetor connects on to the intake manifold of the internal combustion engine with which the carburetor is used.

a throttle valve in said passageway, the said inlet being positioned on the atmosphere side and the said outlet being positioned on the manifold side of said throttle valve, a venturi in said passageway on the outlet side of the throttle valve, a conduit having one end terminating in the venturi and the other end terminating in the carburetor passageway on the atmosphere side of the throttle valve, and a suction controlled ignition timing device connected into said conduit between the ends of the conduit whereby when the throttle valve is partly open the timing is principally controlled by the vacuum on the manifold side of the throttle valve air bled by the portion of the conduit communicating with atmosphere and at wide open throttle the timing is controlled principally by the vacuum created by the flow of air through the venturi past the end of the conduit.

2. Thecombination as claimed in claim 1 having a valve positioned in the conduit responsive to the vacuum on the'outlet side of the throttle valve when in idle position to shut off the suction device from the venturi whereby at idle position the suction device is subjected substantially to atmospheric pressure and the spark is retarded.

3. In an internal combustion engine the combination of an ignition timer and a carburetor having a passageway including a venturi, a throttle valve on the atmosphere side of the venturi, a conduit having an outlet in the venturi and another outlet into the carburetor passageway on the atmosphere side of the throttle valve, a suction device communicating with the abovementioned conduit coordinated with the relatively low vacuum set up in said conduit by said venturi when the throttle is in approximately full load or wide open position whereby the suction device is operatable to control said ignition timer by the said relatively low vacuum in accordance with the speed of the air flowing through the venturi at wide open throttle and whereby when the throttle valve is partly open the suction device is subjected primarily to the engine intake manifold vacuum reduced by air bleeding into the conduit from the atmosphere side of the throttle valve.

4. The combination as claimed'in claim 3 including a valve in the said conduit responsive to the vacuum on the outlet side of the throttle valve in idle position to close ofi theventuri from the suction device and thereby retard the spark at idle.

MARION MALLORY. 

